The current vehicular engine's cooling systems, basically, consist of a single radiator that exchanges heat between the whole coolant existent in the vehicle's engine cooling system (engine block plus cylinder head, hoses, radiator, etc.) and the surrounding air. In such a system, the engine block and cylinder head constitute a part of the flowing circuit, within which the engine block coolant and the cylinder head coolant mix, and vice-versa. Whenever the thermostatic valve is closed (opening temperature not reached), a mechanical pump generates the coolant flow between the engine block and the cylinder head only. As the thermostatic valve starts its opening process (the opening temperature was surpassed), coolant flow occurs inside the whole engine cooling system. The coolant pump continuously absorbs a fraction of the engine power output. In the current systems, there is no precise mass flow rate and coolant temperature control. A substantial amount of the engine power output is wasted by the coolant pump, due to the gross nature of the current system control. The coolant volume in the system is considerably high.
In the independent cylinder head cooling subsystem, according to the present invention, the correspondent flow circuit consists of the following components: cylinder head, electric or electromechanical coolant pump (to generate forced flow in the system), flow-controlling valve (to control the flow rate in the closed circuit), an independent primary radiator (to exchange heat with the surrounding ambient), a coolant temperature sensor (to measure the coolant temperature in a specific position in the flow circuit, and to make possible the control of the system's operation ), and an expansion and filling reservoir.
In the independent reservoir engine block cooling subsystem, according to the present invention, the respective coolant flow circuit consists of the following components: engine block, an independent secondary radiator (to exchange heat with surrounding ambient), and an expansion and filling reservoir.
The independent cooling system for internal combustion engines, according to present invention, is characterized by performing the engine block and the cylinder head cooling independently of each other. For the cylinder head, the cooling is accomplished by means of forced flow of coolant. For the engine block, the cooling is accomplished by means of natural (free) convection caused by buoyancy effects.
The independent cooling system for internal combustion engines, according to the present invention, permits distinct operating-regime temperatures in the cylinder head and in the engine block respectively. As a consequence, one can obtain better control of the engine heat rejection, better control of the air-fuel mixture temperature, better control of the engine pollutant emissions, faster cylinder head warming-up causing reduction in the engine cold-phase period, effective increase in the compression ratio (to much higher values than the currently attainable).
The fact that the independent cooling system for internal combustion engines, according to the present invention, makes it possible an increase in the engine compression ratio to very high values (for both Otto cycle and Diesel cycle engines), characterizes the system itself by causing a substantial increase in the engine thermal efficiency, yielding, as a consequence, lower fuel consumption and lower pollutant gases emissions.
The independent cooling system for internal combustion engines, according to the present invention, is also characterized by making it possible the control of the independent coolant forced flow through the cylinder head. Said control can be done by the Electronic Control Module which controls single- or multi-point fuel injection systems. The Electronic Control Module, via the coolant temperature sensor, measures the coolant temperature in a specified location and, as a function of that value and the engine operating regime (engine load and engine speed), controls the coolant pump and flow-controlling valve operation.
The independent cooling system for internal combustion engines, according to the present invention, also allows the primary and secondary radiators to be located in series or in parallel, in relation to the vehicle's longitudinal axis.